The Baltimore Longitudinal Study of Aging (BLSA), the NIA's major research program on human aging, has been conducted at the Gerontology Research Center since 1958. The overall scientific goals of the BLSA are: 1) To identify differences among individuals of different ages and changes that occur in the serial observations of these individuals with the passage of time; to determine the relative contribution of aging, disease processes, cohort effects and secular effects in producing observed differences and changes; and to establish the degree of interrelation and/or interaction among these factors. 2) To expand scientific understanding about predictors and risk factors for specific diseases and for other end points related to successes and failures of adaptation to aging processes. The BLSA consists of a series of longitudinal and cross-sectional studies of varying degrees of interrelationships oriented toward description, prediction and intervention in human aging processes. Scientists working with BLSA are assigned to 11 sections of 7 laboratories in addition to the LSB. The Chief, LSB, is the Associate Scientific Director, NIA for the BLSA and LSB staff administer and manage the BLSA as well as conduct research with it.